Argonne National Laboratory has developed a superabsorbing hydrogel-based process for the decontamination of cesium from concrete and other porous building materials. This process uses commercially available spray technology, commercially available biocompatible polymers, common chemical reagents, and commercial wet-vacuum technology. It works by spraying a water-based chemical on the concrete surface, followed by spraying the surface with a superabsorbing gel. The gel retains its consistency at relatively high temperatures and humidity for many hours. The gel is removed by wet-vacuum technology, and the resultant material can be dehydrated to significantly reduce the waste volume requiring disposal. While the gel formulation is suitable for cesium decontamination, it is not optimum for decontamination of actinides (e.g., americium), lanthanides, or fission products from porous surfaces, particularly concrete, brick, tile, marble, granite, and asphalt. U.S. Pat. No. 7,737,320, which is incorporated herein by reference in its entirety, describes this Argonne decontamination technology for removal of radioactive cesium from porous surfaces
Decontamination of radionuclides (e.g., actinides, lanthanides, and fission products) from porous surfaces (e.g., concrete, brick, tile, marble, granite, asphalt, and the like) is generally very difficult because the porosity of the surface allows for penetration of the radionuclides below the surface of the material. In fact, there are very few non-destructive options for removal of actinides and other fission product contaminants from concrete, brick, tile, marble, granite, asphalt, and other porous surfaces. Most known decontamination protocols for actinide and other fission products are designed for decontamination of non-porous surfaces, such as metals. These protocols generally involve the use of harsh acids to remove the oxide scales that host the radionuclides. Acidic materials are destructive to many porous construction materials, such as concrete, brick, marble, and brick. In addition, strongly acidic materials are toxic, requiring deployment only in closed or contained environments.
There is an ongoing need for new, more efficient, non-destructive decontamination compositions and methods for removing actinides and lanthanides from porous surfaces. The present invention addresses this ongoing need.